Pump



Filed NOV. 26, 1948 K. HENRICHSEN 2 Sheets-Sheetl l INVENTOR K/VUT HENR/GHSEN Aug 25, 1953 K. HENRlcHsEN 2,649,741

PUMP

Filed NOV. 26, 1948 2 Sheets-SheeiZ IN VEN TOR. K/VU T HEN/P/CHSE N BY /nw MM ATTORNEY Patented Aug. 25, 1953 UNITED STATES :PAT-NT QFFICE PUMP Knut Henrichsen, Los Angeles, Calif., assignor to North American Aviation, Inc.

Application November 26, 1948, Serial No. 62,024

(Cl. 10S-162) friction, with a :corresponding increase in eiliciency.

It is still another object of this invention to Iprovide in a, hydraulic unit of this type novel `features which obtain Yhigh power output for a rdesign of relatively light weight.

vIt is -yet another object of this invention to `provide'in a Vswash plate-type pump a very-great angle 4`between the driving shaft and the driven shaft so as to obtain the maximum stroke.

It is a further object of this invention to provide in a unit of this type a valve which is vfloat- .ingly mounted With respect 'to the cylinder block or cylinder assembly which normally operatively carries the same.

Other objects of invention will becomevapparent from the following description taken in connection with the accompanying drawings, in u which Fig. 1 is a sectional view of applicants improved pump;

-and sleeve arrangement forming a part of this invention taken along the line 4 4 of Fig3 Fig. `5 is a sectional view taken along line 5-5 -of Fig.,l;

Fig. -6 is an `elevational View -partly .in section `vshowing an improved piston forming a part of this invention and Fig. 7 is a sectional view part-ly :in elevation ishowingan improved bearing arrangement forming a part of this invention.

Referring to lthe drawings ythere is .provided la housing I `adapted to receive a `drive member -2 Isuitably mounted therein by antifriction .bears ings 3 and `lI. The drive member is connected by a pair of universal joints referred to generally as A5 and 'S to a combination Aaxle hub and universal joint 'connection "I whichin turnis drivingly Con'- nected by pin and slot arrangement 8 to a cylin- Vder Ablock 9 suitably rotatably mounted on axle Ill by antifriction bearings II and I2. A spring I3V operatively positioned between the axle and cylinder block urge the cylinder block and members-carried therebyinto operative sealing yposition in a manner to be hereinafter more .fully described.

Voperatively mounted -within .the cylinder block in cylinder bores Il are pistons I5 of .particular design to be hereinafter more `fully described. These pistons are .connected Vby rods I6 and ball bearings -I'I to drive-member 2 :and are held in operative position with respect thereto by Aball retainers I8., one retainer being .provided for each ball. These retainers are L-shaped, with an opening for engaging the forward ends of the balls. They are heldin place lby pins I9 `and springs 2i) and are each installed by -tilting the vretaineragainst the action of the spring :2-0 associated `tlfierewith until-a retaining -pin 2| can be placed .in yan opening fin .pin I9. VSprings 120 thereupon hold pins I9 with retaining pins ZI in lsnug relation with drive .member 2. This spring and pin combination (for operatively positioning the ball retainers I8 is so yarranged thatat low speeds only ya small force such as that supplied -through vpins I9 and springs 20 is iapplied tothe :bearing surfaces between retainers Ir8 and ball bearings Il.

This eliminates unnecessary wear and provides low friction 'at ylow speeds. However, as the rotative speed increases there is a greater tendency for-ball bearings yI'I to pull out of their sockets in drive member 2, requiring a greater retaining force. In the presentarrangement this retaining force is automatically obtained with increased speed, resulting in centrifugal acceleration of the 'weight of the retainer itself. Thus, the force tend-ing to pull the connecting rod balls `out of their sockets increases -as the square o'f the R. P. M. Likewise, the centrifugal force of the ball vretainers I 8 increases as the square of `the R. P. M. This is accomplished in the present invention by r'having the ball retainers of such a preselected mass that the resulting action thereof on ball bearings I'I will serve to exert a force on the balls of suicient amount, and in such a direction, that they will be retained in their bearing sockets. yln this connection it is noted that the outer portion 22 of the sockets 4extends forwardly of the inner portion 'thereof in order to assist in providing such a reaction. AS previously described in the specication and illustrated in Fig. 1 of vthe drawing, vL--shaped retainers t8 engag the forward nportion of ball bearings il. When the pump rotates, the centrifugal forcee exerted by these retainers will urge them radially outward against ball portion il. By engaging the forward portions of the balls, the retainers will, when urged outwardly by reason of their rotation, exert a force pushing the balls into the sockets in the general direction of overhanging portion 22. As the speed of rotation increases, the centrifugal force exerted by the retainers will likewise increase and will thus exert a greater force retainl ing the balls in the sockets.

Operatively connected to the forward portion of the cylinder block by gimbals 23, or other suitable universal connection, is a valve 2li having a bearing at 25 on axle lil. Bearing 25 of course may be plain or antifriction, as desired, it being only necessary that the valve be oatingly mounted insofar as its connection with the cylinder block is concerned. The forward portions of the cylinder bores I4 are operatively connected to the valve by means of sleeves 26 and washers 2. The sleeve and washer arrangement functions to eifectively seal the fluid flow through the forward end of bore U and valve port 28 into vsuitable ports 29 and 29a in valve block 3U.

Springs 3l urge the sleeves and washers into sealing engagement with valve 24 and urge the valve into engagement with valve block 3B. From valve block 30 the uid is transmitted through inlet and outlet ports 32 and 33 respectively to a device (not shown) to be actuated by the pump.

The combination of the valve carried by the cylinder block for floating movement with respect thereto permits self-aligning freedom in all directions at each cylinder. This allows the use of a considerably smaller valve diameter than heretofore, resulting in a substantial reduction `of friction loss in the valve face.

Another feature of the invention which reduces friction, leakage, and wear, is a reduction in the diameter of the piston intermediate its ends. Referring now to Fig. 6 the external diameter of piston 1S is reduced intermediate its ends at 34 a small amount-in the neighborhood of a few ten-thousandths of an inch-for the purpose of obtaining desired fluid pressure distribution in the space between the piston and the cylinder wall. This tends to keep the piston centered with respect to the cylinder, with all the resultant advantages of such an arrangement.

Another friction reducing and balancing feature of the present invention comprises the fluid bearing arrangement as shown in Figs. 6 and '7. This feature involves providing piston I with an orice 35 precalculated in area to obtain the results desired for the passage of fluid pressure through an opening 36 in the connecting rod and the connecting 4opening 3'! in bearing I1 to an enlarged area 38 in that bearing for transmitting fluid pressure to take the thrust load of the connecting rod. The area 38 is of such a size as to properly take the thrust in the desired operating range of the pump. Such an arrangement is particularly desirable for reducing static friction in cases where the unit has to start as a motor under heavy load.

A further feature of the pump is the elimination of valve noises and power losses in the operation of the valve ports. Thus, inlet and outlet valve ports 32 and 33, respectively, are arranged .so that the valve will close the individual cylinder port as the corresponding piston reaches the end of its stroke. This is accomplished in the arrangement of Fig. 5 by foreshortening the upper d end of valve port 29 and the lower end of port 29a. Thus the distance a from the centerline of the pump is less than b, and the distance c is less than d. With such an arrangement the fluid on the outlet side of the structure will be slightly compressed before the port is uncovered. Likewise, the opening of the inlet valve is delayed sufficiently long to permit the fluid toexpand slightly before the valve is effectively opened. In the operation of the pump the delayed opening of the valve permits the fluid trapped between the piston and the valve at the beginning of the outlet stroke to be pressurized before the valve opens, so that the pressure is the same on both sides of the valve atthe instant of opening. In a similar Way, pressure is relieved from the fluid trapped between the piston and the valve at the beginning of the intake stroke. Without this increase and decrease of pressure the sudden equalization of pressures in the instant when the port opens would result in considerable power losses because of compressibility shocks, as well as in considerable noise, which would make the pump unsuitable for many purposes.

Although the invention has been described and illustrated in detail, it is to be clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the spirit and scope of this invention being limited only by the terms of the appended claims.

I claim:

l. A pump comprising a housing, a drive member and a cylinder block rotatably mounted in said housing, said cylinder block having bores therein, piston means reciprocably received within said bores, universal joint means connecting said drive member to said cylinder block, a valve block in said housing, said valve block having inlet and outlet ports therein, a valve member connector means securing said valve member to said cylinder block with freedom for universal movement relative thereto whereby said valve member is oatingly carried by said cylinder block for1 voperatively connecting bores in said cylinder block with ports in said valve block. pistons in said bores, ball bearing means connecting said pistons to said drive member, said pistons and bearing means having an opening from the pressure side of said pistons to the pressure side of said bearing means for relieving pressure on said bearing means.

2. A device as recited in claim l and further including means for retaining said ball bearing means in said drive member, said retaining means comprising a ring positioned so as to engage the inner portion of said ball member remote from said drive member so that centrifugal force resulting from rotation thereof will exert a ballretaining force thereon.

3. A pump comprising a housing, a drive member and a cylinder block rotatably mounted in said housing, said cylinder block having bores therein, pistons reciprocably received within said bores, universal joint means connecting said drive member to said cylinder block, a stationary valve block in said housing having inlet and outlet ports therein and a valve member, universal connector means interconnecting said valve member and said cylinder block whereby said valve member is carried by said cylinder block with freedom for universal movement relative thereto, said valve block ports arranged with respect to said valve ports so that fluid to be pumped through said outlet valve block port will be slightly comcgcscyzfri the iluid "to expand -slightly #before said port iis -eiectively opened.

4. A device as recited in claim '3 in which said inlet and outlet ports compriseA arcuate openings t0 be successively interconnected'with said valve vports upon rotation of the-cylinder block and Lvalve with respect to the valve iblock.

5. A pump comprising -arhousing, a valve block xed in said housing, iandshavinginlet and outlet ports therein, an axle fixed to said housing and extending through said valve block, a cylinder block rotatably -mounted Von'saidaxlasaid `cylinder block having bores therein, piston means reciprocably received within said bores, universal joint means connecting said drive member and said cylinder block, a valve member means whereby said valve member is iloatingly carried by said cylinder block with freedom for universal movement relative thereto and having ports connecting bores in said cylinder block with ports in said valve block, sleeve and washer means operatively connecting said bores with said valve ports, spring means operatively associated with said axle and said cylinder block for urging the cylinder block, valve, and valve block into operative engagement, ball means connecting pistons in said bores to said drive member, said balls having a iiuid bearing area thereon, means connecting said area with the pressure side of said pistons to transmit a predetermined thrust to said bearing area, and a ring member for retaining said ball bearings in said drive member arranged so as to engage the inner portions of said ball bearings remote from said drive member, and which is responsive .to rotation of such drive member to exert a force which increases with the speed of rotation thereof urging said ball bearings into engagement with said drive member.

6. A pump comprising a housing, a drive member and a cylinder block rotatably mounted in said housing, said cylinderblock having bores therein, valve means having inlet and outlet ports, universal joint means connecting said drive member with said cylinder block, pistons in said cylinder bores, ball bearing means connecting said pistons with said drive member, a retainer for each ball bearing, spring means for holding said retainers in place for slow rotation of said drive member, each of said retainers being arranged so as to engage the inner portions of said ball bearings remote from said drive member so as to exert increased holding force thereon in response to increased speed of rotation of said drive member.

7. A pump comprising a housing, a drive member and a cylinder block rotatably mounted in said housing, said cylinder block having bores therein, valve means having inlet and outlet ports, universal joint means connecting said drive member with said cylinder block, pistons in said cylinder bores, ball bearing means connecting said pistons with said drive member, said drive member including socket portions for receiving said ball bearings, and a retainer for each ball bearing, said retainers including angle members .having openings therein for engaging said balls, and spring and pin means for operatively positioning said angle members to exert a slight holding force upon slow rotation of said drive member, said retainers exerting an increased holding force on said bores in response to increased speed of rotation of said drive member.

6 i8. A pump comprising a'housinga drive imem- -ber and 1a cylinder block rotatably mounted 2in said housing, lsaid cylinder'block 'having bores therein, 'pistons reciprocably received within said bores, eachofsaid pistonsvhavingf-a recessed fporetion intermediate its `ends "for receiving iiu'id during operationof said pump 'forfce'nteringfsaid piston, universal vjoint -means connecting -said drive member to said cylinder block, a stationary valveblock in said housing having inlet and outlet ports therein, and a valve member carried by said cylinder blockwith freedom for universal movement relative thereto, v.said valve member having Aports therein for connecting said cylinder block bores with said valve block ports.

9. A pump comprising a housing, a drive member and a cylinder block rotatably mounted in said housing, said cylinder block having bores therein, piston means reciprocally received within said bores, universal joint means connecting said drive member to said cylinder block, a valve block in said housing, said valve block having inlet and outlet ports therein, a valve member, and means interconnecting said valve member and said cylinder block whereby said valve member is carried thereby with freedom for universal movement with respect thereto and operatively connects the bores in said cylinder block with the ports in said valve block.

10. A pump comprising a housing, a drive member rotatably mounted therein and adapted to be connected to a source of power, a cylinder block in said housing at an angle to said drive member, said cylinder block being provided with a plurality of bores therethrough, piston means reciprocally received within said bores, universal joint means connecting said drive member to said cylinder block, a valve block in said housing, said valve block having inlet and outlet ports therein, a valve member, and universal connector means interconnecting said valve member and said cylinder block whereby said valve member is carried thereby with freedom for universal movement with respect thereto and operatively connects the bores in said cylinder block with the ports in said valve block.

11. A pump comprising a housing, a drive member and a cylinder block rotatably mounted in said housing, said cylinder block having bores therein, pistons reciprocally received within said bores, universal joint means connecting said drive member to said cylinder block, a valve block xedly mounted in said housing, said valve block having inlet and outlet ports, a valve, universal connector means interconnecting said valve and said cylinder block whereby said valve is carried thereby with freedom for universal movement relativethereto, said valve having bores therein adapted to communicate with said valve block ports, and sleeve means connecting said cylinder block bores with said valve bores whereby said valve operatively connects said cylinder block bores with said valve block ports.

12. A device as recited in claim 1l and further including spring means urging said cylinder block, valve, and valve block into operative engagernent.

13. A pump comprising a housing, a drive member and a cylinder block rotatably mounted in said housing, said cylinder block having bores therein, pistons reciprocally received within said bores, universal joint means connecting said drive member to said cylinder block, a valve block in said housing, said valve block having inlet and outlet ports therein, a valve member, universal connector means interconnecting said valve member and said cylinder block'whereby said Valve member is oatingly carried by said cylinder block, and spring means urging said cylinder block, valve, and valve block in operative relationship With freedom for universal movement therebetween whereby said valve connects bores in said cylinder block with ports in said valve block.

KNUT HENRICHSEN.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 1,618,805 Brawner Feb. 22, 1927 1,710,567 Carey Apr. 23, 1929 Number Number 15 580,593

Name Date Surber May 6, 1930 Thoma Apr. 25, 1939 Thomas Aug. 8, 1939 Doe May 15, 1941 Vickers May 26, 1942 Zimmermann July '7, 1942 Wegerdt Sept. 29, 1942 Snader et al Oct. 20, 1942 Molly Aug. 14 ,1945 Purcell Nov. 7, 1950 FOREIGN PATENTS Country Date Great Britain 1946 

